Guidance Note 2: Isolation & Switching provides clear guidance on what can be a confusing aspect of BS 7671. It is ideal for those working in design, testing and inspection and maintenance and operational aspects and has been fully updated to BS 7671:2018+A4:2026, including isolation of multipole source systems, guidance on the selection of protective, isolation and switching devices; bidirectional and unidirectional devices and Firefighters switches.